In handheld kitchen appliances, for example handheld blenders, attachable accessories are used to provide a variance of use of the same appliance, for example bars, choppers, and the like are provided as accessories that can be releasably attached to a main unit, which may contain the motor, the electronic system as well as the housing. In order to allow an easy change of the respective accessories, depending on the user's particular needs or demands, a release mechanism may be provided that is activatable by the user. For example, two buttons on opposing sides may be provided to be pushed by the user for releasing a locking mechanism, such that the accessory can be released from the main unit. For example, U.S. Pat. No. 5,567,047 describes a handheld blender including a motor assembly and a tool assembly, releasably connectable to the motor assembly. For mounting the tool assembly to the motor assembly, the motor assembly has a U-shaped expansion clamp and the tool assembly has a tool shank with a mounting groove, which is engaged by the U-shaped expansion clamp. To release the tool shank, the expansion clamp is displaced by a push button in the direction of an opposite push button, having expansion surfaces on which the legs of the expansion clamp ride up, thus disengaging the expansion clamp from the mounting groove. Thus, by moving, i.e. activating, the two push buttons in the direction towards each other, the expansion clamp is displaced by a translational movement in its plane in the direction to the push button with the expansion wedge, having expansion surfaces against which the clamp legs abut with their free ends. By reason of the use of two push buttons for releasing the tool shank, whereof one operates to displace the expansion clamp in the direction of the other push button, while at the same time the other push button, acting in opposition to this displacement, urges the expansion wedge into the space between the leg ends of the expansion clamp, the two push buttons are required to travel only a short distance for actuation. EP 1 138 239 B1 describes a handheld mixer, comprising a housing which contains a drive motor and with which a shank part is detachably connected. To couple the shank part to the motor housing, a retaining groove is provided in which a retaining element engages. In order to release the engaging element, a closed ring-like structure is provided as the retaining element, which by applying a pressing force on two opposite sides, is buckled. Since the retaining element is formed as a closed frame structure, the buckling leads to a decrease in the width in direction of the applied pressing forces, and to an increase in the width in an opposite direction. By providing respective projections to engage the retaining groove, on the side portions between the opposite push buttons, the buckling leads to a disengagement of the engaging projections from the retaining groove, thus releasing the attached accessory part. However, it has been shown that upon wear and the entry of dirt, the mechanisms to be activated by the user may require an activation force which contributes to a decrease in experienced user comfort.
FR 2 854 561 relates to a machine for preparing foodstuff and describes a releasably attached tool.